The invention arose during continuing development efforts directed to providing a low cost oximeter sensor assembly with integral cable, and particularly to improved calibration and encoding.
Oximeters are known in the art, and are used by anesthesiologists for continuous intraoperative noninvasive monitoring of arterial oxygen saturation of the patient under anesthesia, Anesthesiology News, Volume 13, Number 7, July 1987, pages 1, 66, 68 and 69, and also for neo-natal monitoring, and for various other uses. The oximeter provides a prewarning of hypoxia. A sensor having light emitting diodes and a light receiving element is placed around a finger tip, a toe, an ear lobe, the nose, etc. The effect of the patient's blood and its oxygen content on the intensity of light at a particular wavelength of light received by the light receiving element from the light emitting diodes give a measure of the oxygen content in the blood, U.S. Pat. Nos. 4,621,643, 4,653,498, 4,685,464, 4,700,708, 4,770,179, 4,825,879, 4,830,014, incorporated herein by reference.
The invention in the noted parent application provides an oximeter sensor assembly with integral cable. The assembly is characterized by low material cost, low assembly cost, suitability for high volume automated manufacturing as well as variable quantity manufacturing. The assembly provides a high degree of mechanical flexibility, and also offers full electromagnetic interference shielding if desired.
The invention of the noted parent application offers a significant commercial advantage in that it reduces cost by a factor of 7. This 7:1 cost advantage makes the sensor assembly disposable, which is deemed highly desirable.
The present invention provides a particularly simple and cost effective encoder on the substrate strip of the parent invention for calibration of the oximeter.